Replace c-blosc extension

Author: dstansby

numcodecs/__init__.py

@@ -52,9 +52,7 @@
         ncores = multiprocessing.cpu_count()
     except OSError:  # pragma: no cover
         ncores = 1
-    blosc.init()
     blosc.set_nthreads(min(8, ncores))
-    atexit.register(blosc.destroy)
 
 with suppress(ImportError):
     from numcodecs import zstd

numcodecs/blosc_v2.py renamed to numcodecs/blosc.py

@@ -52,20 +52,30 @@
 
 
 def list_compressors() -> list[str]:
+    """Get a list of compressors supported in blosc."""
     return blosc.compressor_list()
 
 
 def get_nthreads() -> int:
+    """
+    Get the number of threads that Blosc uses internally for compression and
+    decompression.
+    """
     nthreads = blosc.set_nthreads(1)
     blosc.set_nthreads(nthreads)
     return nthreads
 
 
 def set_nthreads(nthreads: int) -> None:
+    """
+    Set the number of threads that Blosc uses internally for compression and
+    decompression.
+    """
     blosc.set_nthreads(nthreads)
 
 
-def cbuffer_complib(source):
+def cbuffer_complib(source) -> str:
+    """Return the name of the compression library used to compress `source`."""
     return blosc.get_clib(source)
 
 
@@ -86,6 +96,32 @@ def _check_buffer_size(buf, max_buffer_size):
 
 
 def compress(source, cname: str, clevel: int, shuffle: int = SHUFFLE, blocksize=AUTOBLOCKS):
+    """
+    Compress data.
+
+    Parameters
+    ----------
+    source : bytes-like
+        Data to be compressed. Can be any object supporting the buffer
+        protocol.
+    cname : bytes
+        Name of compression library to use.
+    clevel : int
+        Compression level.
+    shuffle : int
+        Either NOSHUFFLE (0), SHUFFLE (1), BITSHUFFLE (2) or AUTOSHUFFLE (-1). If AUTOSHUFFLE,
+        bit-shuffle will be used for buffers with itemsize 1, and byte-shuffle will
+        be used otherwise. The default is `SHUFFLE`.
+    blocksize : int
+        The requested size of the compressed blocks.  If 0, an automatic blocksize will
+        be used.
+
+    Returns
+    -------
+    dest : bytes
+        Compressed data.
+
+    """
     if shuffle == AUTOSHUFFLE:
         if source.itemsize == 1:
             shuffle = BITSHUFFLE
@@ -109,6 +145,23 @@ def compress(source, cname: str, clevel: int, shuffle: int = SHUFFLE, blocksize=
 
 
 def decompress(source, dest: np.ndarray | bytearray | None = None):
+    """
+    Decompress data.
+
+    Parameters
+    ----------
+    source : bytes-like
+        Compressed data, including blosc header. Can be any object supporting the buffer
+        protocol.
+    dest : array-like, optional
+        Object to decompress into.
+
+    Returns
+    -------
+    dest : bytes
+        Object containing decompressed data.
+
+    """
     if dest is None:
         return blosc.decompress(source)
     elif isinstance(dest, np.ndarray):
@@ -119,7 +172,8 @@ def decompress(source, dest: np.ndarray | bytearray | None = None):
 
 
 class Blosc(Codec):
-    """Codec providing compression using the Blosc meta-compressor.
+    """
+    Codec providing compression using the Blosc meta-compressor.
 
     Parameters
     ----------
@@ -170,11 +224,5 @@ def decode(self, buf, out=None):
         return decompress(buf, out)
 
     def __repr__(self):
-        r = '%s(cname=%r, clevel=%r, shuffle=%s, blocksize=%s)' % (
-            type(self).__name__,
-            self.cname,
-            self.clevel,
-            _shuffle_repr[self.shuffle + 1],
-            self.blocksize,
-        )
+        r = f'{type(self).__name__}(cname={self.cname!r}, clevel={self.clevel!r}, shuffle={_shuffle_repr[self.shuffle + 1]}, blocksize={self.blocksize})'
         return r